Effect of communicating phenotypic and genetic risk of coronary heart disease alongside web-based lifestyle advice

Objective: To determine whether provision of web-based lifestyle advice and coronary heart disease risk information either based on phenotypic characteristics or phenotypic plus genetic characteristics affects changes in objectively measured health behaviours. Methods: A parallel-group, open randomised trial including 956 male and female blood donors with no previous history of cardiovascular disease (mean [SD] age = 56.7 [8.8] years) randomised to four study groups: control group (no information provided); web-based lifestyle advice only (lifestyle group); lifestyle advice plus information on estimated 10-year coronary heart disease risk based on phenotypic characteristics (phenotypic risk estimate) (phenotypic group); and lifestyle advice plus information on estimated 10-year coronary heart disease risk based on phenotypic (phenotypic risk estimate) and genetic characteristics (genetic risk estimate) (genetic group). The primary outcome was change in physical activity from baseline to 12 weeks assessed by wrist-worn accelerometer. Results: 928 (97.1%) participants completed the trial. There was no evidence of intervention effects on physical activity (difference in adjusted mean change from baseline): lifestyle group vs control group 0.09 milligravity (mg) (95%CI: -1.15 to 1.33); genetic group vs phenotypic group -0.33 mg (-1.55 to 0.90); phenotypic group and genetic group vs control group -0.52 mg (-1.59 to 0.55); and vs lifestyle group -0.61 mg (-1.67 to 0.46). There was no evidence of intervention effects on secondary biological, emotional and health-related behavioural outcomes except self-reported fruit and vegetable intake. Conclusions: Provision of risk information, whether based on phenotypic or genotypic characteristics, alongside web-based lifestyle advice did not importantly affect objectively measured levels of physical activity, other health-related behaviours, biological risk factors or emotional well-being. Clinical Trial Registration: Current Controlled Trials ISRCTN17721237. Prospectively registered 12 January 2015. http://www.isrctn.com/ISRCTN17721237. Key words: cardiovascular disease; genetics; primary prevention; risk assessment; risk reduction behaviour
This work was supported by a European Commission Framework 7 EPIC-CVD Grant agreement no: 279233. NHS Blood and Transplant funded the INTERVAL trial. DNA extraction and genotyping in INTERVAL/INFORM was funded by the National Institute for Health Research. The coordinating team for INTERVAL/INFORM at the Cardiovascular Epidemiology Unit of the University of Cambridge was supported by core funding from: UK Medical Research Council (G0800270), British Heart Foundation (SP/09/002), British Heart Foundation Cambridge Cardiovascular Centre of Excellence and UK National Institute for Health Research Cambridge Biomedical Research Centre. BS was supported by the Medical Research Council [MC_UU_12015/4].